Hermetic compressor

ABSTRACT

A hermetic compressor comprising a horizontal motor-compressor unit in which the motor component and a reciprocal compressor component are of substantially the same transverse configuration and are so arranged relative to one another as to provide a compact unit which can be housed in a symmetrical casing with all major portions of the unit spaced about the same distance from the casing walls.

limited States Patent Inventor Robert E. Rogers Sidney, Ohio Appl. No. 851,280

Filed Aug. 19, 1969 Patented Aug. 17, 1971 Assignee General Electric Company HERMETIC COMPRESSOR 7 Claims, 4 Drawing Figs.

U.S.Cl 417/312, 417/415 Int. Cl ..F04b 39/00,

F 04h 35/04 Field of Search 230/232,

[56] References Cited UNITED STATES PATENTS 3,141,608 7/1964 Enemark 230/232 3,189,255 6/1965 Enemark... 230/58 3,317,121 5/1967 DeGroat.... 230/58 3,419,207 12/1968 Hintze 230/235 Primary Examiner-Robert M. Walker Attorneys-Walter E. Rule, Harry F. Manbeck, J11, Joseph B.

Forman, Oscar B. Waddell and Frank L. Neuhauser ABSTRACT: A hermetic compressor comprising a horizontal motor-compressor unit in which the motor component and a reciprocal compressor component are of substantially the same transverse configuration and are so arranged relative to one another as to provide a compact unit which can be housed in a symmetrical casing with all major portions of the unit spaced about the same distance from the casing walls.

PATENTED Ans] nan I 3500.111,

sum 1 or 2 IN V If N TOR.

ROBERT E. ROGERS Fl /ZZDW,

H\ ATTORNEY Pmmwmmmn 3,600,111

' SHEET 2 OFZ INVENTOR. ROBERT E. ROGERS H 15 ATTOR NEY HERMETIC COMPRESSOR BACKGROUND OF THE INVENTION Size, operating noise level and cost are three important criteria in the design of hermetic compressors for household refrigerators. The size of the hermetic casing required to house a given motor-compressor unit is important since the space required in the cabinet for the compressor cannot be used for refrigerated storage space. Also for the same compressor capacity, the smaller the compressor, the greaterthe potential for saving on the material cost. Noise level is largely dependent upon case design. Unless rather heavy or thick casing material is used or resonant or noise damping devices added to the casing, it is desirable that the casing be of a symmetrical configuration characterized by continuously curving rather than flat surfaces. Thus to meet all three criteria, it is desirable that the motor compressor unit be compact and of a configuration fitting or matching the optimum case configuration with a minimum wasting of the space between the motor compressor unit and casing surfaces.

SUMMARY OF THE INVENTION A general object of the present invention is to provide in a hermetic compressor, a motor-compressor unit adapted to be housed in a relatively small, symmetrical casing with a minimum waste of space within that casing.

In accordance with the illustrated embodiment of the invention, there is provided a hermeticcompressor comprising a symmetrical casing containing a horizontally disposed motorcompressor unit including a motor component and a compressor component. The compressor component includes a cast frame having an end wall including a horizontal axis bearing portion and an annular wall which defines with the end wall a crankcase portion surrounding the bearing portion. The frame also includes a cylinder portion extending radially and horizontally from the crankcase portion. The means for connecting the compressor frame to the motor stator comprises a pair of spaced legs respectively above and below the cylinder portion and a third leg on the opposite side of the frame from the cylinder portion. The stator includes an annular flux carrying portion or yoke having a pair of spaced ears extending outwardly therefrom to respectively engage the pair of spaced legs on the compressor frame. These ears which are out of the general flux path of the yoke include holes for bolts connecting the stator to the frame. By this construction the stator and the compressor frame are of substantially the same transverse shape and configuration and the space between the spaced ears on the stator is used to contain a tubular discharge muffler connected to the cylinder head. Preferably the compressor frame also includes an arcuate chamber above the crankcase portion forming an intake muffler for the compressor.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing:

FIG. 1 is a horizontal section view of a hermetic compressor of the present invention;

FIG. 2 is a vertical view, partly in section, of the hermetic compressor oflFiG. ll;

FIG. 3 is a view of the compressor or front end of the motor compressor unit with a portion of the casing removed; and

FIG. 4 is a view of the motor or rear end of the unit with the portion of the casing cutaway.

DESCRIPTION OF THE PREFERRED EMBODIMENT The hermetic compressor illustrated in the accompanying drawing comprises a hermetic casing ll comprising substantially symmetrical upper and lower case portions 2 and 3 having overlapping edge portions joined by a welded seam 4. The hermetic casing 1 houses a motor compressor unit generally indicated by the numeral 5 which includes a motor component 6 and a compressor component 7 and which is resiliently and horizontally supported in spaced relationship with the walls of the casing 2.

The compressor component 7 includes a compressor frame 8, which is preferably cast metal, and which includes an end wall 9 containing a horizontal axis bearing 10 and an annular wall 11 that together with a portion of the end wall 9 defines a crankcase cavity 12. The opposite end of the compressor frame is formed by a bearing plate 1 secured to the member 8 as by means of bolts 15. The plate 1 3 includes a bearing 16 axially aligned with the bearing 10. A crankshaft 17 is journaled in these bearings 10 and 16.

The frame 8 also includes a cylinder portion 19 opening into and extending radially and horizontally from the crankcase portion 12. The cylinder portion 19 supports a compressor cylinder 20 containing a reciprocating piston 2i connected by rod 22 to an eccentric 23 formed on the portion of the shaft 17 within the crankcase 12.

At the outer or head end of the cylinder 20, there is provided a head and valve structure in which a valve plate 26 is clamped between a cylinder head 27 and the finished outer surface of the cylinder 20; the head 27 being secured to the cylinder portion 19 by bolts 28. The valve plate 26 includes a plurality of radially extending inlet ports 29 on one side thereof and a plurality of discharge or outlet ports 30 on the other side thereof. The inlet ports communicate with the interior of the cylinder 20 through an intake valve 31 while the discharge ports 30 communicate with the interior of the compressor head 27 through a discharge valve 33.

In accordance with the usual practice, mufiling means are provided for the refrigerant gas flowing to and from a compressor cylinder 20. In accordance with the present invention, the intake muffling means comprises a muffler chamber 35 cast into the compressor frame 8 as an arcuate chamber which is generally above the crankcase portion 12. Gas from the interior of the casing 2 enters the intake muffler 35 through a tube 36 and a fitting 37 as shown in FIG. 3. The intake muffler 35 has an outlet portion 38 which, as is shown in FIG. 1 of the drawing, is to one side of the cylinder portion 19. It is connected by a passage 39 formed in the frame 8 to an annular passage 40 partially surrounding the valve plate 26 and in communication with the intake ports 29.

The high pressure gas discharged through the compressor head 27 is conducted through a discharge muffler 41 connected to the head 27 by a tube 42 and from the discharge muffler 41 through a discharge tube 43 exiting through the compressor casing 11.

The motor 6 employed in the practice of the invention is a relatively small, highly efficient, two-pole induction motor of the type more fully described in the copending application of William R. Hoffmeyer and Alvin L. Rediger, Ser. No. 840,188 filed July 9, 1969, and assigned to the same assignee as the present invention. It comprises a rotor 46 mounted on the motor end of the shaft i7 and a stator 47 secured by bolts 48 to the frame 8. The stator is particularly characterized by the fact that it includes, as shown in FIG. 4 of the drawing, a pair of spaced projections or ears 49 extending radially outwardly from the annular body portion or yoke 50 of the stator and having mounting openings through which two of the three bolts employed to secure the stator to the frame 8 pass. More specifically the stator is oriented with reference to the frame 8 so that these cars 49 are respectively above and below the cylinder component 19 of the frame 8 and the frame 8 is provided with spaced legs 52 for threadably receiving the bolts passing through the ears 49. The third bolt 48a for providing a tripod connection of the stator to the frame 8 passes through the yoke portion of the stator on the opposite side thereof from the ears 49 and threads into a leg 52a provided at that portion of the frame 8. The two legs 52 and the third leg 52a are of lengths sufficient to space the stator 47 from the outer surface of the frame wall 9 and provide the room required for the adjacent end turns of the motor run windings 54 and start windings 55.

By employing the spaced ears 49 to secure the stator to the frame 8, a substantial reduction in the stator size is possible due to the fact that the bolt receiving holes in the ears 49 are out of the normal or principal magnetic flux area or yoke of the stator thereby eliminating the magnetic restriction of boltholes within the main or yoke portion of the stator. Thus the general-periphery or transverse configuration of the stator can be relatively small and generally within or matching the transverse configuration of the frame 3.

Preferably the motor is wound so that, as shown in FIG. 4 of the drawing, the run windings are respectively above and below the ears 49 or more specifically generally within the arcuate yoke portions between these ears and the opening for bolt 48a passing through the stator yoke. Thus, the bolthole receiving the bolt 48a is between the run windings and has less effect on the magnetic efficiency of the stator.

As a further means for arranging the components of the motor compressor unit as compactly as possible, the exhaust muffler 41 is nested within the V-shaped recess between the radially extending ears 49 and is of a relatively long tubular shape so that its outer surface, as shown for example in FIGS. 3 and 4 of the drawing, is substantially in line with the outer end of the cylinder head 27 and its length, as shown in FIGS. 1 and 2 of the drawing, is such that it does not extend beyond the rear ends of the motor windings. As a further .means of providing a compact motor compressor unit, the discharge tube 43 leading from the exhaust muffler 41 passes upwardly therefrom to a point above the upper ear 49 but below the top of the stator and then forwardly around the front end of the compressor frame 8 then rearwardly to a point rearward of the stator after which it curves beneath the stator before suitably exiting through the case 1. By this routing, most of the tubing 43-is within the general rectangular configuration of the motor compressor unit.

For the purpose of providing lubrication to the various moving parts of the motor compressor unit and for the purpose of cooling the motor component, there is employed a lubricating system including rotary pump 57 driven by the shaft 17. This pump as shown in FIGS. 1 and 3 comprises an annular chamber 58 defined by an annular bore in the end bearing plate 14 and a cap 59 secured to the bearing plate. Chamber 58 contains an eccentric 60 rotated by the shaft 17. A vane 61 extending through the wall of the chamber 58 is biased into engagement with the peripheral surface of the eccentric 60. Upon rotation of the eccentric 60, oil is drawn into the pumping chamber 58 through line 62 from a body of lubricant provided in the bottom of the casing 1 and is discharged from the chamber through a passage 63 in the cap 59 to a header 64 in the cap adjacent the end of the shaft 17. Some of this oil passes through a longitudinal, axially offset passage 65 in the shaft 17 and into the three transverse passages 66, 67 and 68 for respectively conveying lubricant to the bearings 16, 23, and 10.

As shown in FIG. 1 of the drawing, the longitudinal passage 65 extends substantially the full length of the shaft 17 which is provided with two additional transverse passages 69 adjacent the opposite ends of the rotor 46, these passages passing through the axis of rotation of the shaft 17 and serving the dual purpose of maintaining a substantial back pressure on the oil in passage 65 by the centrifugal action thereof and also discharging some oil onto the rotor 46 from which it is thrown onto the stator windings for cooling these windings.

Another and a much smaller portion of the oil from the header 64 is conducted through a capillary tube 70 (FIG. 3) to the inlet end of the suction line 36 where it is metered into the suction gas entering the compressor to provide the required lubrication for the compressor cylinder and piston area of the compressor. A third portion of the oil is conveyed through a line 71 to an oil cooler tube 72 extending outwardly, as indicated in FIG. 1 of the drawing from the casing 1.

Any suitable resilient support means may be employed for supporting the motor compressor unit within the casing 1. In the illustrated embodiment of the invention three substantially identical compression springs 75 are employed with one of these springs in a position beneath the frame component 8 and the other two springs engaging the opposite ends of a strap 76 brazed or welded to the bottom of the stator 47. These three springs provide a three-point resilient suspension system for permitting limited movement of the motor compressor unit within the casing 1 in the well-known manner.

From an examination of each of the figures of the accompanying drawing, it will be seen that by the above-described construction of the compressor frame 8 and the motor 6 and the specific orientation of the motor rotor 47 with reference to the frame 8 as well as the positioning of the exhaust muffler 41 between the ears 4-9, there is provided a motor compressor unit having substantially rectangular, horizontal and vertical contours or configurations with substantially all of the space within the rectangular contour being occupied by essential operative components of the motor compressor unit. it is thus possible to house the motor compressor unit within a symmetrical casing having substantially the same generally rectangular configuration but preferably, as shown in FIGS. 1 and 2 of the drawing, having somewhat curved rather than flat walls. The curvature of the casing walls is selected to minimize the noise level of the hermetic compressor but the overall configuration thereof is such that in both the horizontal and vertical planes, that is at all points about the unit there is substantially the same space or clearance between adjacent portions of the motor compressor unit and the casing. The net result is a relatively small, low cost and low profile hermetic compressor.

While there has been shown and described a specific embodiment of the invention it will be understood that it is not limited thereto but it is intended by the appended claims to cover all such modifications as fall within the spirit and scope of the invention.

What i believe is new and desire to secure by Letters Patent of the United States is:

1. A hermetic compressor comprising a hermetic casing containing a horizontally disposed motor-compressor unit including a motor component and a compressor component;

said compressor component comprising a compressor frame including an end wall containing a horizontal axis bearing portion, a forwardly extending annular sidewall defining with said end wall a crankcase portion surrounding said bearing portion, and a cylinder portion extending radially and horizontally from said crankcase portion; said frame including a pair of spaced legs respectively above and below the axis of said cylinder portion and a third leg on the opposite side of said frame from said cylinder portion, said legs extending rearwardly from the outer surface ofsaid bottom wall of said frame; said motor component comprising a stator including spaced ears respectively engaging said pair of spaced legs and means for securing said ears to said pair of spaced legs;

means including a cylinder head containing a compressor discharge cavity secured to said frame at the outer end of said cylinder portion;

a discharge muffler nested in the space between said stator ears, and

a discharge line connecting said discharge cavity to said muffler and supporting said muffler on said frame.

2. The compressor of claim I in which said ears include boltholes for receiving bolts securing said stator to said frame.

3. A hermetic compressor comprising a hermetic casing containing a horizontally disposed motor-compressor unit including a motor component and a compressor component;

said compressor component comprising means including a compressor frame defining an annular crankcase portion and a cylinder portion extending radially and horizontally from said crankcase portion;

said frame including a pair of spaced legs respectiveiy above and below the axis of said cylinder portion and a third leg on the opposite side of said frame from said cylinder portion, said legs extending from the outer surface of said frame;

said motor component comprising a stator including spaced ears respectively engaging said pair of spaced legs and having boltholes therein, bolts in said holes for securing said stator to said pair of spaced legs;

a discharge muffler nested in the space between said stator V said motor component comprising a stator including a yoke section and spaced ears extending radially from one side of said yoke section;

and means for connecting said ears to said frame respectively above and below said cylinder portion including spaced legs on said frame for connection to said ears, said legs spacing said motor stator from said compressor frame.

5. The compressor of claim 4 including a discharge muffler positioned adjacent said motor between said ears.

6. The compressor of claim 5 in which said motor component, compressor component and muffler present a unit of substantially rectangular cross section.

7. The compressor of claim 5 in which said compressor component frame includes a arcuate chamber above said crankcase portion. 

1. A hermetic compressor comprising a hermetic casing containing a horizontally disposed motor-compressor unit including a motor component and a compressor component; said compressor component comprising a compressor frame including an end wall containing a horizontal axis bearing portion, a forwardly extending annular sidewall defining with said end wall a crankcase portion surrounding said bearing portion, and a cylinder portion extending radially and horizontally from said crankcase portion; said frame including a pair of spaced legs respectively above and below the axis of said cylinder portion and a third leg on the opposite side of said frame from said cylinder portiOn, said legs extending rearwardly from the outer surface of said bottom wall of said frame; said motor component comprising a stator including spaced ears respectively engaging said pair of spaced legs and means for securing said ears to said pair of spaced legs; means including a cylinder head containing a compressor discharge cavity secured to said frame at the outer end of said cylinder portion; a discharge muffler nested in the space between said stator ears, and a discharge line connecting said discharge cavity to said muffler and supporting said muffler on said frame.
 2. The compressor of claim 1 in which said ears include boltholes for receiving bolts securing said stator to said frame.
 3. A hermetic compressor comprising a hermetic casing containing a horizontally disposed motor-compressor unit including a motor component and a compressor component; said compressor component comprising means including a compressor frame defining an annular crankcase portion and a cylinder portion extending radially and horizontally from said crankcase portion; said frame including a pair of spaced legs respectively above and below the axis of said cylinder portion and a third leg on the opposite side of said frame from said cylinder portion, said legs extending from the outer surface of said frame; said motor component comprising a stator including spaced ears respectively engaging said pair of spaced legs and having boltholes therein, bolts in said holes for securing said stator to said pair of spaced legs; a discharge muffler nested in the space between said stator ears, said compressor component, motor component and muffler forming a compact unit having a substantially rectangular contour, said casing being shaped to conform substantially to the contour of said unit.
 4. A hermetic compressor comprising a hermetic casing containing a horizontally disposed motor-compressor unit including a motor component and a compressor component; said compressor component comprising means including a compressor frame defining an annular crankcase portion and a cylinder portion extending radially and horizontally from said crankcase portion; said motor component comprising a stator including a yoke section and spaced ears extending radially from one side of said yoke section; and means for connecting said ears to said frame respectively above and below said cylinder portion including spaced legs on said frame for connection to said ears, said legs spacing said motor stator from said compressor frame.
 5. The compressor of claim 4 including a discharge muffler positioned adjacent said motor between said ears.
 6. The compressor of claim 5 in which said motor component, compressor component and muffler present a unit of substantially rectangular cross section.
 7. The compressor of claim 5 in which said compressor component frame includes a arcuate chamber above said crankcase portion. 